Hijacking of host cellular functions by an intracellular parasite, the microsporidian Anncaliia algerae

PLoS One. 2014 Jun 26;9(6):e100791. doi: 10.1371/journal.pone.0100791. eCollection 2014.

Abstract

Intracellular pathogens including bacteria, viruses and protozoa hijack host cell functions to access nutrients and to bypass cellular defenses and immune responses. These strategies have been acquired through selective pressure and allowed pathogens to reach an appropriate cellular niche for their survival and growth. To get new insights on how parasites hijack host cellular functions, we developed a SILAC (Stable Isotope Labeling by Amino Acids in Cell culture) quantitative proteomics workflow. Our study focused on deciphering the cross-talk in a host-parasite association, involving human foreskin fibroblasts (HFF) and the microsporidia Anncaliia algerae, a fungus related parasite with an obligate intracellular lifestyle and a strong host dependency. The host-parasite cross-talk was analyzed at five post-infection times 1, 6, 12 and 24 hours post-infection (hpi) and 8 days post-infection (dpi). A significant up-regulation of four interferon-induced proteins with tetratricopeptide repeats IFIT1, IFIT2, IFIT3 and MX1 was observed at 8 dpi suggesting a type 1 interferon (IFN) host response. Quantitative alteration of host proteins involved in biological functions such as signaling (STAT1, Ras) and reduction of the translation activity (EIF3) confirmed a host type 1 IFN response. Interestingly, the SILAC approach also allowed the detection of 148 A. algerae proteins during the kinetics of infection. Among these proteins many are involved in parasite proliferation, and an over-representation of putative secreted effectors proteins was observed. Finally our survey also suggests that A. algerae could use a transposable element as a lure strategy to escape the host innate immune system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA Transposable Elements / genetics
  • Fibroblasts / cytology
  • Fibroblasts / parasitology
  • Fungal Proteins / metabolism
  • Host-Parasite Interactions*
  • Humans
  • Intracellular Space / metabolism
  • Intracellular Space / parasitology*
  • Microsporidia / genetics
  • Microsporidia / metabolism
  • Microsporidia / physiology*
  • Proteome

Substances

  • DNA Transposable Elements
  • Fungal Proteins
  • Proteome

Grants and funding

This work was funded by a grant, Projets Exploratoires Pluridisciplinaires (PEPS) from the Centre National de la Recherche Scientifique (France) (CNRS SILACFOOD). J.P. was supported by a scholarship from the Ministère de l'Education Nationale de l'Enseignement Supérieur et de la Recherche (France). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.